FIG. 1 depicts a diagram of the salient components of wireless telecommunications system 100 in the prior art. Wireless telecommunications system 100 comprises: base stations 101-1 through 101-3, wireless terminal 102, wireless switching center 111, location client 112, and location server 113, interrelated as shown. Wireless telecommunications 100 provides wireless telecommunications service to all of geographic region 120, in well-known fashion.
Each of base stations 101-1 through 101-3 comprises a clock. The clock enables each event that occurs as part of the base station's operations to be assigned the time at which the event occurs. Examples of such events include, but are not limited to, i) transmission of a particular signal, ii) reception of a particular signal, iii) initiation of a communication session, and iv) termination of a communication session.
In some wireless telecommunications systems in the prior art, each base station synchronizes its clock with an external time reference that is common to all base stations in the system. An example of such an external time reference is one that is based on the Global Positioning System (GPS). In such synchronized systems, when an event occurs at a base station, the time at which it occurs is known relative to the external time reference. As a result, because all base stations synchronize their clocks to the same external reference, it is possible to know the relative timing of events that occur, across the different base stations.